Valve Covers Whistling when PCV connected??? wtf?

DMX

Registered User
Custom project, supercoupe blower on Taurus 3.8 engine
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Ran 3/8" power steering hose to connections in both valve covers, and connect then with a T-connector

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That T-connector is then connected to "C" above, i have been told that is the connection for the PCV.

I am pulling about 21inHg at idle, whenever i have the PCV connected as stated above there is this high pitched wavering whisting (weeweweweweeeweee) noise from the valve cover area, if you give it a little gas and the vacuum drops for a sec it goes away then slowly returns.

After the car is shut off, you can hear it whistling and "bleeding" out as the vacuum gauge slowly returns to zero over the course of about 10 seconds.

That noise is very annoying and weird, and if gear the oil light will flicker a bit in sync with the wavering "weweweweeweeee" noise.

Whats up with that? I've had to resort to simply capping that PCM vacuum connection and letting the T-connector simply breathe free under the hood.

What am I doing wrong here?

Thanks in advance,
DMX
 
that C goes to the valve cover/PCV with the #1-3 cylinders(also attaches to somewhere else), cylinders #4-6 are hooked to the air inlet tube after the MAF thru the valve cover(not manifold vacuum)
 
Connect either B or F to E.
A is for your boost/vacuum gauge.

Have you listened closely to the bypass valve to see if it's leaking? That might be the source of your noise.

Also, no sense in leaving C open now is there? That would simply be a huge vacuum leak. By the way, I have both valve covers connected to C and the only consequence is a little bit more oil usage.

Saw your project a while back, keep at it, hope you get it runnin' right.

'bird

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tbird88 said:
Connect either B or F to E.
A is for your boost/vacuum gauge.

Have you listened closely to the bypass valve to see if it's leaking? That might be the source of your noise.

Also, no sense in leaving C open now is there? That would simply be a huge vacuum leak. By the way, I have both valve covers connected to C and the only consequence is a little bit more oil usage.

Saw your project a while back, keep at it, hope you get it runnin' right.

'bird

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Why would you connect both valve covers to C? Now your pulling unmetered air into the intake system[BAD thing to do] Not to mention you are pulling one hell of a vaccume on the crankcase and pulling MORE oil into the intake system.[which is why you are using more oil now] Connect the left valve cover to the air intake tube between the throttlebody and the MAF and your whistling will stop.
 
Originally posted by MIKE 38sc
Why would you connect both valve covers to C? Now your pulling unmetered air into the intake system[BAD thing to do] Not to mention you are pulling one hell of a vaccume on the crankcase and pulling MORE oil into the intake system.[which is why you are using more oil now] Connect the left valve cover to the air intake tube between the throttlebody and the MAF and your whistling will stop.

Doesn't matter, the air from the left cover is still unmetered air because it enters after the MAF. Yes, the EEC is supposed to be calibrated for the additional air that's normally entering just after the MAF but apparently it has no effect in my case. True, I keep vacuum on the driver cover but my car idles like crap if I connect it to the intake tube after the MAF. She runs fantastic set up the way she is, and believe me, you don't want to know when her last spark plug change was...(I don't know).

to j57ltr with love: yeah lightweight, you read that right, the last person to see the spark plugs in this engine was the last owner (1 1/2 years ago).

'bird
 

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tbird88 said:


Doesn't matter, the air from the left cover is still unmetered air because it enters after the MAF. Yes, the EEC is supposed to be calibrated for the additional air that's normally entering just after the MAF but apparently it has no effect in my case. True, I keep vacuum on the driver cover but my car idles like crap if I connect it to the intake tube after the MAF. She runs fantastic set up the way she is, and believe me, you don't want to know when her last spark plug change was...(I don't know).

to j57ltr with love: yeah lightweight, you read that right, the last person to see the spark plugs in this engine was the last owner (1 1/2 years ago).

'bird
Well actually Tbird the hose that is connected between the throttlebody and the Maf is the inlet for fresh air into the cranckcase. Vaccume opens the PCV valve pulling air from the crankcase while fresh air is let into the system through the hose on the left valve cover and since the air is coming in AFTER it has gone through the MAF it is METERED. Not to mention with your set up your piston rings are now trying to work with vaccume on the backside! This is NOT GOOD and WILL cause problems with sealing. You already stated that you use more oil now, and that is the cause. Keep doing it and you will be replacing the rings before much longer, if you havent already hurt them.:)
 
My bad on the flow direction on the driver cover, but just for kicks does anyone know the facts about direction of airflow in that tube versus throttle position?
As far as oil consumption on my car, almost a quart every 2 months but then again you'd have to see her parking spot in the street out in front of the house and in the carport out back. That's where 90% of the oil went, on the ground. 30,000 miles plus on the set up, I ain't lost the rings yet & don't anticipate it happening.
Why?...I've run sustained vacuum on older PCV systems for 30 years now without a vent, heck, most were untouched factory systems. And then the environmental police came along...

Only thing I can see doin' different would be to put a breather/filter (one of them cute little K&N jobs) on the driver cover.

'bird

Show of hands: How many 13 second cars still connect to the inlet tube?

ps: great thread!
 
tbird88 said:
My bad on the flow direction on the driver cover, but just for kicks does anyone know the facts about direction of airflow in that tube versus throttle position?
As far as oil consumption on my car, almost a quart every 2 months but then again you'd have to see her parking spot in the street out in front of the house and in the carport out back. That's where 90% of the oil went, on the ground. 30,000 miles plus on the set up, I ain't lost the rings yet & don't anticipate it happening.
Why?...I've run sustained vacuum on older PCV systems for 30 years now without a vent, heck, most were untouched factory systems. And then the environmental police came along...

Only thing I can see doin' different would be to put a breather/filter (one of them cute little K&N jobs) on the driver cover.

'bird
Yes, I know the FACTS about the airflow through that tube and posted them. Maybe you are leaking alot of oil, but youre also sucking a bunch more into your intake because of your set up. Wanna bet? Maybe you havent lost your rings yet. Do you run cats? You've really got my interest up on this sustained vaccume system that you've run for 30 years.[how old are you? I thought I was old] Could you explain the layout of that system? I cant seem to grasp it. Help me out please. Your statment about the 13 sec. cars really doesnt have anything to do with this thread, its compairing apples to oranges.

Show of hands: How many 13 second cars still connect to the inlet tube?

ps: great thread!
[/QUOTE/]
 
just remembered, C goes to PCV and carbon cannister.
That line from B is right if it goes to the main vacuum harness of the vehicle(vacuum for accesories), I was thinking of RWD hose routing.

Vacuum in the crank-case does help rings seal:D, they actually make pumps to pull a few inches
 
I dont know what car it was on, maybe some later model Mustang, but someone said it might have one, or something to do with how the air pump was connected:confused:

Might of been on that 429?? later BOSS" for all I know:D
 
AsScLoWn said:
I dont know what car it was on, maybe some later model Mustang, but someone said it might have one, or something to do with how the air pump was connected:confused:

Might of been on that 429?? later BOSS" for all I know:D
No Mustang has ever come with that system! Not even the BOSS 429! My buddy has a BOSS 429 and there is no such system on it. The only thing I've seen that on is highly specialized race cars and most of them were circle track cars. This type of system would be horible for the street.
 
AsScLoWn said:
this was a 94up with a 429 or something
Oh so your talking about some custom built something? In that case anythings possable, but that does'nt make it practical or even usable or even desireable on the street.
 
I know, I zoned out when the guy said some "Mustang" had it, he might of been talking about that specially built one, who knows, I never payed too much attention
 
Ugh, let's not talk about getting old. Anyways...cars went the longest with oil filler caps that didn't vent to the atmosphere or to the air cleaner housing. Guess I'd like to eventually have the fancy breather I mentioned. I was gonna use one on my 88TC but never got around to it. Oughta look spiffy, especially in chrome, might even add a little bot of R value to my car :)

Guess it's just me, I don't have the piping from the driver side valve cover to the inlet tube & don't plan on it in the future...just a vented CHROME filter on the driver cover (ooooh so sexy!).

'bird
 
tbird88 said:
Ugh, let's not talk about getting old. Anyways...cars went the longest with oil filler caps that didn't vent to the atmosphere or to the air cleaner housing. Guess I'd like to eventually have the fancy breather I mentioned. I was gonna use one on my 88TC but never got around to it. Oughta look spiffy, especially in chrome, might even add a little bot of R value to my car :)

Guess it's just me, I don't have the piping from the driver side valve cover to the inlet tube & don't plan on it in the future...just a vented CHROME filter on the driver cover (ooooh so sexy!).

'bird
Yeah not my favorite subject either, but its a fact of life. I'm not trying to tell you what to do with your car, its yours and you can do what you want with it. I just thought that maybe you had not considered that with the system you just described you WILL be pulling in unmetered air and the ECU is NOT setup to take care of that. I believe you would agree that if the fella left his connection at point C in his picture open he has a GIANT vaccume leak. Think about it for a moment, you will have the same leak with your set up. You will have only moved the leak to the air breather filter that you put into the valve cover. I've been down this road before, the car will not want to idle it will hunt! The RPM's will go up and down while trying to idle and will eventually die. Just trying to save you some trouble thats all.:)
 
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